What is engine knock

Running your car with engine knock leads to excessive wear and could even lead to engine failure. What causes the knocking sound coming from your engine?

Your engine depends on two primary ingredients in order to fire and create the power that propels you forward: oxygen from the air around you, and fuel that can be ignited. When exposed to a spark, the ignited fuel consumes the air, creating the explosion. This is all controlled via a number of mechanical components, including your timing belt and crankshaft. Should any of these features break, bend, or otherwise adjust, the timing between all of these different sequences could be thrown off, causing your engine to run poorly or even stop working completely.

Here are a few of the most common solutions to knocking issues. It's a simple process, but if you're uncomfortable or don't have the right tools, it's best left to a mechanic.

Once the plugs are out, compare the model numbers stamped onto the plugs with your manufacturer's recommendation which can be found in your owner's manual. If the spark plugs were the right kind, well, it's a good thing you're probably already at your mechanic's, because your car's got other problems.

Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Under the Hood. Engine Performance. What is engine knock? Hey, what's that knocking noise in the engine? See more pictures of engines. Engine Knock Causes Fuel should burn in even waves that are timed to the engine's cycles, carrying through until the next cycle causes the next wave. Low quality fuel One of the causes of engine knock is sub-par gasoline -- low quality and low octane fuel can cause a whole cluster of problems, such as increased combustion chamber temperatures and higher cylinder pressures.

How is engine knock fixed? It's easy to misdiagnose the cause of engine knock, so you might have to pay a visit to your mechanic. They can lead to combustion chamber deposit buildup and improper running temperatures. What causes an engine knock? Low quality fuel, deposits on the cylinder walls and using the wrong spark plugs can lead to an engine knock.

How do you fix an engine knock? Try using higher quality fuel. Carbon Buildup. Home Noise from engine or exhaust Inspection. The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details. Excellent Auto Repair Ratings. YourMechanic Auto Repair. Related Articles. How Does a Distributor Work?

What Is Engine Displacement? Experienced Mechanic? Recent Noise from engine or exhaust Inspection reviews. Excellent Rating. Rating Summary. Andrew 11 years of experience. Request Andrew. Ford Focus L Andy has worked on our cars for years. He is so nice and always on time. He always explains everything very well and has just been great to work with! Andrew looked and said that the fan blades were no aligned with the the Fan Housing.

We then listened and I told him it could be the impeller in the water pump but the sound wasn't "metallic". He said that the impellers in my water pump were a plastic composite. He was right on both accounts. What a PRO! Unfortunately, some deposits still form. As you learned with fuel, changes in fuel compression can lead to nasty knocking sounds. Why it matters: Excess carbon buildup can lead to problems in the combustion process and damage your engine's cylinders.

The resulting decrease in performance can also lead to lower gas mileage or overheating. Noticing a theme? What to do: Have your cylinders cleaned by a professional. Briggs and Stratton , an engine manufacturer, recommends that you check your cylinder for carbon build-up every hours of operation, just to be safe. If you're short on time and expertise, feel free to bring your car to your local Firestone Complete Auto Care for an inspection and tune-up.

Our technicians can help your engine get back in shape! If your car's engine knocking has you stumped, stop by your nearest Firestone Complete Auto Care and let our technicians get to the bottom of the noise. Depending on your vehicle, manufacturer recommendations , and mileage, a maintenance tune-up may be just what your car needs. The solution could be as simple as a basic spark plug replacement, or it may require more in-depth adjustments.

Schedule your appointment online today! It's time to make your drive smooth and quiet again.